In a 57-page opinion, U.S. District Judge Emmet G. Sullivan said a former Ringling employee, Tom Rider, and the Animal Protection Institute did not have legal standing to sue the circus under the Endangered Species Act.

Rider and the institute had argued that Ringling Bros. had violated the Endangered Species Act because handlers used bull hooks on elephants and chained them for long periods. Such techniques harmed the elephants, Rider and API argued.

Attorneys for Feld Entertainment, Ringling's parent company, replied that the elephants were not abused and were, in fact, loved by their trainers.

If Sullivan had found a violation of the Endangered Species Act, Ringling Bros. would have had to stop the practices in question or obtain an exemption from the Interior Department.

Instead, the judge ruled that Rider, a former animal trainer, did not prove he had a strong attachment to the animals, a requirement under the law. The judge also questioned Rider's credibility, noting that he had been paid tens of thousands of dollars by API and other animal rights groups over the years.

"The court finds that Mr. Rider is essentially a paid plaintiff and fact witness who is not credible, and therefore affords no weight to his testimony," Sullivan wrote.

The judge found that API did not have standing on more technical legal grounds.

"We are disappointed that the judge dismissed the suit without considering the merits," said Adam Roberts, executive vice president of API.

API was joined in the suit by the American Society for the Prevention of Cruelty to Animals, the Animal Welfare Institute and the Fund for Animals. Because API does not have standing under Sullivan's ruling, the other groups also cannot press the matter.